低浓度碱介质中钢渣碳酸化反应特征

Reaction characteristics of steelmaking slag carbonation in dilute alkali medium

钢渣碳酸化是一种CO_2矿化利用的有效方法。通过添加低浓度碱,可有效提高钢渣碳酸化转化效率。围绕低浓度碱介质中钢渣碳酸化过程,系统研究了搅拌转速、低浓度碱浓度、反应温度等工艺条件对钢渣碳酸化转化效率的影响。在搅拌转速为450 r/min,碱浓度为20 g/L,反应温度为70℃等优化工艺条件下可实现钢渣碳酸化转化效率为49.72%,是传统水介质体系的1.8倍以上,且反应条件温和,介质可循环利用。进一步开展了钢渣碳酸化反应动力学研究,结果表明钢渣碳酸化反应为内扩散控制,计算得到表观活化能为22.48 k J/mol。

Steelmaking slag carbonation mineralization is an effective method for CO2 in-situ fixation. The rate of steelmaking slag carbonation process could be enhanced by adding alkali medium with low concentration. The influences of processing conditions, such as stirring speed, reaction temperature and dilute alkali concentration, on carbonation efficiency were systematically studied. The optimal carbonation conditions are. stirring speed of 450 r/min, temperature of 70 ℃ , dilute alkali concentration of 20 g/L. Under optimal conditions, the carbonation efficiency is approximately 49.72%, almost 1.8 times as high as traditional water system. At the same time, the reaction condition is mild, the dilute alkali can be recycled in this process. Reaction kinetics model of the steelmaking slag carbonation was established. The results show that the steelmaking slag carbonation reaction was controlled by internal diffusion, and the calculated apparent activation energy is 22.48 kJ/mol.